#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <dirent.h>
#include <sys/stat.h>
void do_ls(char[]);
void dostat(char *);
void show_file_info( char *, struct stat *);
void mode_to_letters( int , char [] );
char *uid_to_name( uid_t );
char *gid_to_name( gid_t );
int main(int argc, char *argv[])
{
if ( argc == 1 )
do_ls( "." );
else
while ( --argc ){
printf("%s:\n", *++argv );
do_ls( *argv );
}
return 0;
}
void do_ls( char dirname[] )
{
DIR	*dir_ptr;	
struct dirent	*direntp;	
if ( ( dir_ptr = opendir( dirname ) ) == NULL )
fprintf(stderr,"ls1: cannot open %s\n", dirname);
else
{
while ( ( direntp = readdir( dir_ptr ) ) != NULL )
dostat( direntp->d_name );
closedir(dir_ptr);
}
}
void dostat( char *filename )
{
struct stat info;
if ( stat(filename, &info) == -1 )	
perror( filename );	
else	
show_file_info( filename, &info );
}
void show_file_info( char *filename, struct stat *info_p )
{
char	*uid_to_name(), *ctime(), *gid_to_name(), *filemode();
void	mode_to_letters();
char modestr[11];
mode_to_letters( info_p->st_mode, modestr );
printf( "%s" , modestr );
printf( "%4d " , (int) info_p->st_nlink);	
printf( "%-8s " , uid_to_name(info_p->st_uid) );
printf( "%-8s " , gid_to_name(info_p->st_gid) );
printf( "%8ld " , (long)info_p->st_size);
printf( "%.12s ", 4+ctime(&info_p->st_mtime));
printf( "%s\n" , filename );
}
void mode_to_letters( int mode, char str[] )
{
strcpy( str, "----------" );
if ( S_ISDIR(mode) ) str[0] = 'd';
if ( S_ISCHR(mode) ) str[0] = 'c';
if ( S_ISBLK(mode) ) str[0] = 'b';
if ( mode & S_IRUSR ) str[1] = 'r';
if ( mode & S_IWUSR ) str[2] = 'w';
if ( mode & S_IXUSR ) str[3] = 'x';
if ( mode & S_IRGRP ) str[4] = 'r';
if ( mode & S_IWGRP ) str[5] = 'w';
if ( mode & S_IXGRP ) str[6] = 'x';
if ( mode & S_IROTH ) str[7] = 'r';
if ( mode & S_IWOTH ) str[8] = 'w';
if ( mode & S_IXOTH ) str[9] = 'x';
}
#include <pwd.h>
char *uid_to_name( uid_t uid )
{
struct	passwd *getpwuid(), *pw_ptr;
static char numstr[10];
if ( ( pw_ptr = getpwuid( uid ) ) == NULL ){
sprintf(numstr,"%d", uid);
return numstr;
}
else
return pw_ptr->pw_name ;
}
#include <grp.h>
char *gid_to_name( gid_t gid )
{
struct group *getgrgid(), *grp_ptr;
static char numstr[10];
if ( ( grp_ptr = getgrgid(gid) ) == NULL ){
sprintf(numstr,"%d", gid);
return numstr;
}
else
return grp_ptr->gr_name;
} 
